Stone tools hint at the origins of the modern human mind

Study suggests complex behaviors were handed down for tens of thousands of years.

Despite intense scientific inquiry, there are still major gaps in our knowledge about early human life. One major question that remains unanswered: when humans were first capable of complex cognition? In other words, when did early humans develop sophisticated cognitive abilities, such as prioritization and cultural transmission, that we would recognize today?

A new study in Nature addresses this; after six years of excavation, archaeologists have unearthed technologically-advanced stone tools that were created about 71,000 years ago. This finding enhances our knowledge about the history of human tool use, suggesting that sophisticated cognitive abilities were present relatively early in human history. It also raises the possibility that tools may have given early humans an advantage as they ventured out of Africa.

The ancient tools, called microliths, were found at a site called Pinnacle Point in South Africa. Microliths are small stone tools—less than 50mm in length—that are heat-treated and trimmed into specific shapes. The “bladelets” found at Pinnacle Point closely resemble tools from other sites that were used as the points of arrows and other compound projectile weapons. However, optical dating techniques suggest the Pinnacle Point tools are 6,000 to 10,000 years older than those found at other sites. So humans may have created and used bows and arrows earlier than previously thought.

Not only is this finding interesting in terms of weaponry, but the complex process required to make microliths suggests these early humans had surprisingly modern cognitive abilities. Early humans would have needed to identify and collect the mineral needed for the blade and the wood needed for the heat source, prepare the blades, create and maintain the controlled fire to heat-treat them, reshape the heated blades into microliths, carve wood or bone into shafts, and mount the microlith on the shaft to form a compound tool. Furthermore, the researchers believe microlithic technology persisted at Pinnacle Point for at least 11,000 years, indicating that this intricate process must have been passed down across multiple generations. Following—and passing along—this “recipe” implies microlith-makers living more than 70,000 years ago were capable of foresight, prioritization of tasks, and cultural transmission. All of those are certainly sophisticated cognitive capabilities.

Other studies have used symbolic representation, such as body ornaments and carved decorations, as a proxy for the modern human mind. These types of objects generally appear in the archaeological record between 100,000 and 60,000 years ago. However, critics have argued the thoughts motivating the creation and use of these objects is unclear, and therefore they are not a good proxy for advanced cognition. The authors of the Nature study disagree, saying that complex ideas and transmission are a better way to measure what makes a human mind “modern.” Interestingly, the age of the Pinnacle Point microliths—71,000 years—falls squarely in the range of when scientists believe symbolic representation first appeared on the scene.

The researchers assert the skill associated with making microliths would have been hugely beneficial to early humans. Projectile weapons such as bows and arrows would allow them to kill with greater accuracy and from longer distances. Microlithic technology may have given early modern humans an advantage over both prey and Neanderthals, assisting their migration from Africa and perhaps enabling their eventual spread across the globe.

I myself found it interesting. Pushing back the timeline for advanced cognition by 6000-10000 years is newsworthy in some circles. For others it might just be interesting. In either case I enjoy these articles.

Also, by proxy it pushes the arrival of the monolith back a bit further as well......

I don't think it is a surprise at all. We really haven't changed much in the last 70,000 year even 100,000 I would say. The biggest changes have had to do with disease resistance and living so close to one another.

I'm interested to know what exactly was gained by heat treating. It doesn't seem like they would get the rocks hot enough to melt and reform, but more likely that they would either heat a stone to make it more brittle and easier to create a blade form by chipping, or that they would chip the shape first and then heat treat it to either temper or anneal the material.

I don't think it is a surprise at all. We really haven't changed much in the last 70,000 year even 100,000 I would say. The biggest changes have had to do with disease resistance and living so close to one another.

I'm interested to know what exactly was gained by heat treating. It doesn't seem like they would get the rocks hot enough to melt and reform, but more likely that they would either heat a stone to make it more brittle and easier to create a blade form by chipping, or that they would chip the shape first and then heat treat it to either temper or anneal the material.

I'm interested to know what exactly was gained by heat treating. It doesn't seem like they would get the rocks hot enough to melt and reform, but more likely that they would either heat a stone to make it more brittle and easier to create a blade form by chipping, or that they would chip the shape first and then heat treat it to either temper or anneal the material.

"Furthermore, the researchers believe microlithic technology persisted at Pinnacle Point for at least 11,000 years"

Presumably it was refined across this period somewhat? Even so it's striking that a relatively complex process continued across such a timespan sufficiently unmodified to remain recognisable - ie that it wasn't supplanted by substantially different technology. Had they reached a local maximum with that technology and it needed a real breakthrough such as metallurgy, or are there more advanced types of stone weapon tooling that wouldn't be identified as Pinnacle Point-like?

Even so it's striking that a relatively complex process continued across such a timespan sufficiently unmodified to remain recognisable

I get the impression that actively looking for ways to do things better is not really part of the general human condition. Our current state of access to people who aren't like us (and do things differently) and our relative acceptance of doing things differently from our forefathers is, historically speaking, a bit of an aberration.

I've always thought that the reason that technological progress went hand-in-hand with trade with different cultures was not simply seeing people use other technologies, but that it also made it easier for such people to accept that idea that things *could* change.

Even so it's striking that a relatively complex process continued across such a timespan sufficiently unmodified to remain recognisable

I get the impression that actively looking for ways to do things better is not really part of the general human condition. Our current state of access to people who aren't like us (and do things differently) and our relative acceptance of doing things differently from our forefathers is, historically speaking, a bit of an aberration.

I've always thought that the reason that technological progress went hand-in-hand with trade with different cultures was not simply seeing people use other technologies, but that it also made it easier for such people to accept that idea that things *could* change.

Yeah, the further back you go the slower the rate of change seems to be in general. Olduwan hand axe technology for instance was uniform from 2.6 to 1.7 mya, 900k years with no noticeable progress (though the technology spread all over Eurasia during this time period). Acheulean technocomplex follows and itself lasted at least as long as Olduwan (from 1.7 mya to about 300 kya) though it probably overlaps with later techniques and you start to get into really diverging culture complexes at that point. Anyway, the point is progress was SLOW. Imagine being a Mousterian tool using human living in the levant 150 kya. The tools you make will be INDISTINGUISHABLE from those made by your descendants 100 ky later (that's 5,000 GENERATIONS). Heck, some tech that actually did change noticeably in 11 ky? That's fast advancement.

Even later in neolithic and early historical periods there was very little noticeable progress. Certainly no person living then would likely have noticed even one single change in any detail of their society. As far as they would have been concerned history didn't exist. Life was an unchanging round that had always been as it was and always would be. They weren't far off from right either.

I don't think it is a surprise at all. We really haven't changed much in the last 70,000 year even 100,000 I would say. The biggest changes have had to do with disease resistance and living so close to one another.

I wouldn't be so sure about that. I'm pretty sure that during many generations in prehistoric times cleverness and tool making expertise were a true evolutionary advantage. Especially in a species that spread over all climate zones and oceans and whatnot.

I myself found it interesting. Pushing back the timeline for advanced cognition by 6000-10000 years is newsworthy in some circles. For others it might just be interesting. In either case I enjoy these articles.

Also, by proxy it pushes the arrival of the monolith back a bit further as well......

Funny, I kept thinking the same thing while reading through this, how it's absolutely extraordinary how humans have progressed from not using tools at all to creating supercomputers in less than 100,000 years, when compared to how long other types of animals have been around. Has to be a monolith buried around here somewhere.

Interesting that man went from horse and buggy to the beginnings of industrialization to flight and the moon and technology in about 200 years. Makes one wonder w.t.f has really been going on for the past THREE-HUNDRED-FIFTY multiples of that time (200 x 350 = 70,000). 70k years seems like a very LONG time from the perspective of a sub-century lifespan.

Anyway, I'm thinking about Ötzi, the ~3300yo mummy from the Alps and his way cool axe with the copper blade (~1000 years before the "bronze-age"). That axe-head/blade, which when I first saw it seemed to me to be quite remarkable in it's shaped consistency and rather difficult to hand-forge, reminds me of the middle microlith above, not to mention his own microliths.

I've always thought that there was a general correlation between our current state of advancement, and the speed of further advancement.

Moore's law is a perfect example. We don't add a million transistors to a piece of silicon each year, we double the number. At one point, that meant adding ten transisters, now we're adding millions or billions.

Very slow improvements in primitive tools would eventually get us to the state where we were able to mine or manipulate better materials, leading to slightly better tools, which were themselves improved, and the cycle would continue.

Now we're at the stage where our computers are the main tools. Faster computers mean better, more accurate models, which means we can improve our computers even further.

I don't know how this is going to continue in the future. We clearly still have a great deal to learn about the world, scientifically. But at the same time, we have gadget manufacturers releasing new generations of tech every year. Apple just released a new iPad after 6 months. At some point, the speed of technological improvement is going to overtake our tolerance for constantly acquiring the latest kit. But at the same time, any software written for your current gadget will be totally unable to run on something 6 months (and 4 tech generations) old.

In reality, we know very little about how human beings lived even 1000 years ago. But a look at the big picture suggests a likely pattern. Our use of language is at the center of our cognitive behavior and what distinguishes us from our nearest relatives in the primate world. That use of language depends on our use of our vocal cords as a tool to produce sounds that can influence the behavior of other human beings. The time period for our divergence from other primates is something like 5 million years. So I would suggest that the initial evolution was in the increased dexterity required for more effective tool use starting from the kind of base that is observed today for chimps. Eventually that capability for more complex manipulation of tools lead to a more sophisticated use of sounds which stimulated the evolution of language. The selective advantage resulting from more sophisticated language use is what drove the evolution of our more advanced cognitive abilities. Perhaps there was some quantum evolution. But more likely, given the central role of our cognitive abilities in what makes us human, the process probably went on over an extended part of that 5 million year history.

In reality, we know very little about how human beings lived even 1000 years ago. But a look at the big picture suggests a likely pattern. Our use of language is at the center of our cognitive behavior and what distinguishes us from our nearest relatives in the primate world. That use of language depends on our use of our vocal cords as a tool to produce sounds that can influence the behavior of other human beings. The time period for our divergence from other primates is something like 5 million years. So I would suggest that the initial evolution was in the increased dexterity required for more effective tool use starting from the kind of base that is observed today for chimps. Eventually that capability for more complex manipulation of tools lead to a more sophisticated use of sounds which stimulated the evolution of language. The selective advantage resulting from more sophisticated language use is what drove the evolution of our more advanced cognitive abilities. Perhaps there was some quantum evolution. But more likely, given the central role of our cognitive abilities in what makes us human, the process probably went on over an extended part of that 5 million year history.

Them is many guesses. You'd be surprised how many different reasonable sounding ideas people have had about how it MIGHT have happened. There is of course only limited evidence, so...

That being said, I've often speculated about what a society and technology from a species that uses a beak as a primary appendage would look like.

True, but nature does have possible solutions, IE elephants for instance.

It's amazing what enough time for natural selection can produce, really. A prehensile nose? Not bad.

After watching the cockatiel video in the above story I'm now envisioning a spaceship with climbing grids all over the walls with control panels designed to be beak friendly. Buttons, sliders, latches. I wonder how birds would adapt to zero-g?

An elephant ship would have a giant holographic waterhole-like interface that the elephants could manipulate with their trunks.

I don't think it is a surprise at all. We really haven't changed much in the last 70,000 year even 100,000 I would say. The biggest changes have had to do with disease resistance and living so close to one another.

I wouldn't be so sure about that. I'm pretty sure that during many generations in prehistoric times cleverness and tool making expertise were a true evolutionary advantage. Especially in a species that spread over all climate zones and oceans and whatnot.

How are you thinking of this? That they had to start from scratch over and over again to make it an evolutionary advantage? They learned a technology of fire, they found fire when you heat certain stone it makes it brittle and easily chiseled to sharp shapes. What cleverness and tool making needed to be learned over and over...they just used and adjusted what they had for many tens of thousands of years.

They big thing that happened to move things forward was having more people who could specialize, this happened when we developed and adopted domesticated foodstuffs and husbandry. This took many many generations to develop. Previous to this there was only small groups of 50 to maybe 500 people. Specialization and the time to learn allowed us to develop smelting (another fire advantage with the right rock). Writing and Paper was developed to help administer the populations. Money developed to trade work, this begat taxes instead of paying with service.

If you look genetically we haven't changed much in the last 100,000 years, the stuff that changes is mostly with disease resistance. Brain size has remained relatively the same.

And we did this until we found out about metals, which were hidden in rock. A modern analog would be using carbon nanotubes for electronics. (IBM gangnam style for when Moore's law hits the size limit.) Nanotubes are spontaneously formed in organic combustion flames, but no one noticed.

Makes you wonder what we are missing now.

As for earlier rate of technology progress being "slow", as far as I know it is on much the same exponential as today. (Which is behind the kook Kurzweil's fuzzy so non-predictive "predictions".) When taking the lower population density et cetera under consideration, as I understand it we have always invented at much the same rate as individuals.

So whatever we do differently from other apes, the trait developed before the modern-neanderthal-denisovan split. Some notes down a trait that could distinguish us from other animals, apprenticeship: "monkey see, monkey do" vs "human teach, human is taught".

After that we don't need to be much different. John Hawks has pointed out that the exponential population increase means smaller fitness differences gets picked up and fixated by selection. That means much is secondary our progress to become a major population.

And we did this until we found out about metals, which were hidden in rock. A modern analog would be using carbon nanotubes for electronics. (IBM gangnam style for when Moore's law hits the size limit.) Nanotubes are spontaneously formed in organic combustion flames, but no one noticed.

Makes you wonder what we are missing now.

As for earlier rate of technology progress being "slow", as far as I know it is on much the same exponential as today. (Which is behind the kook Kurzweil's fuzzy so non-predictive "predictions".) When taking the lower population density et cetera under consideration, as I understand it we have always invented at much the same rate as individuals.

So whatever we do differently from other apes, the trait developed before the modern-neanderthal-denisovan split. Some notes down a trait that could distinguish us from other animals, apprenticeship: "monkey see, monkey do" vs "human teach, human is taught".

After that we don't need to be much different. John Hawks has pointed out that the exponential population increase means smaller fitness differences gets picked up and fixated by selection. That means much is secondary our progress to become a major population.

I don't look at it as exponential. It is changing for a number of factors, the biggest one is being the energy available to us from fossil fuels. With it something like 2% of the population currently makes food for everyone. Institutionalization of education, standardization, globalization, simple methods for sharing information, competitive behaviours to drive advancement. But most of all the absolute easy access to massive energy to perform what we want when we want it's like the roman equivalent of having a gang of slaves for every person in the industrialized world, without having to feed or house them.

I looked at a number of places and they were saying that brain sizes have changed little in the last 200,000 years. The 10-20% might have been from Neanderthal to Humans.

Yeah, the further back you go the slower the rate of change seems to be in general. Olduwan hand axe technology for instance was uniform from 2.6 to 1.7 mya, 900k years with no noticeable progress (though the technology spread all over Eurasia during this time period). Acheulean technocomplex follows and itself lasted at least as long as Olduwan (from 1.7 mya to about 300 kya) though it probably overlaps with later techniques and you start to get into really diverging culture complexes at that point. Anyway, the point is progress was SLOW. Imagine being a Mousterian tool using human living in the levant 150 kya. The tools you make will be INDISTINGUISHABLE from those made by your descendants 100 ky later (that's 5,000 GENERATIONS). Heck, some tech that actually did change noticeably in 11 ky? That's fast advancement.

Even later in neolithic and early historical periods there was very little noticeable progress. Certainly no person living then would likely have noticed even one single change in any detail of their society. As far as they would have been concerned history didn't exist. Life was an unchanging round that had always been as it was and always would be. They weren't far off from right either.

This really paints a picture. Because of you, for a few minutes today I imagined what it would be like to live in a static culture of that period.

I don't think it is a surprise at all. We really haven't changed much in the last 70,000 year even 100,000 I would say. The biggest changes have had to do with disease resistance and living so close to one another.

I wouldn't be so sure about that. I'm pretty sure that during many generations in prehistoric times cleverness and tool making expertise were a true evolutionary advantage. Especially in a species that spread over all climate zones and oceans and whatnot.

How are you thinking of this? That they had to start from scratch over and over again to make it an evolutionary advantage? They learned a technology of fire, they found fire when you heat certain stone it makes it brittle and easily chiseled to sharp shapes. What cleverness and tool making needed to be learned over and over...they just used and adjusted what they had for many tens of thousands of years.

They big thing that happened to move things forward was having more people who could specialize, this happened when we developed and adopted domesticated foodstuffs and husbandry. This took many many generations to develop. Previous to this there was only small groups of 50 to maybe 500 people. Specialization and the time to learn allowed us to develop smelting (another fire advantage with the right rock). Writing and Paper was developed to help administer the populations. Money developed to trade work, this begat taxes instead of paying with service.

If you look genetically we haven't changed much in the last 100,000 years, the stuff that changes is mostly with disease resistance. Brain size has remained relatively the same.

I would suspect there was a lot of backsliding, and without a real concrete concept of experimentation and "things can be improved" you see a lot of interesting stuff. For instance Olduwan (mode 1) stone tools are used right alongside later Aurignacian etc tools (modes 2-3 at least). In other words there was either a lot of backsliding and constant reinvention or even when a better way to make a chopper was discovered it wasn't just automatically applied to a scraper as well. People were probably as smart as we are, but population densities were VERY low and it may well be that innovations were simply very rarely passed on. 99% of the time if you invented a new scraper you taught it to your children and the whole group died off 10 years later. Likewise we see fire used sporadically up to 2 million years ago, but it is hard to tell if it was something that spread as a standard technology at that time or if different groups just figured it out again and again in different places. EVENTUALLY we get to a point where advance seems to pile on top of advance, but not before populations start to rise and thoroughly modern people are on the scene.

I don't look at it as exponential. It is changing for a number of factors, the biggest one is being the energy available to us from fossil fuels.

I am not sure I understand. One metric for technological progress would be invention, and as I suggested I suspect the number is exponential (as Kurzweil rely on) purely for exponential population increase.

Those two factors together assures us what is the usual idea of exponential increase in resources, consumption, "progress", et cetera.

Mydrrin wrote:

I looked at a number of places and they were saying that brain sizes have changed little in the last 200,000 years. The 10-20% might have been from Neanderthal to Humans.

Here is a handy summary. It is a bit clustered up, but the probability mass and average of archaic H. sapiens seems to be well above the modern size. [ http://www.pandasthumb.org/archives/200 ... ini_2.html ] Eye-balling it is ~ 0.2 % brain-to-body mass difference, which is ~ 0.002*100 = 200 g diff, or ~ 10 - 20 of a ~ 1.5 kg brain.

I also note that the envelop of the neanderthal brain-to-body mass quotient lies over other groups at the time measured.

Kate Shaw Yoshida / Kate is a science writer for Ars Technica. She recently earned a dual Ph.D. in Zoology and Ecology, Evolutionary Biology and Behavior from Michigan State University, studying the social behavior of wild spotted hyenas.